Denver Broncos quarterback Peyton Manning (18) throws the ball during the second half against the Philadelphia Eagles at Sports Authority Field in Denver on Sept. 29, 2013. / Chris Humphreys, USA TODAY Sports

by Lindsay H. Jones, USA TODAY Sports

by Lindsay H. Jones, USA TODAY Sports

DENVER - As much as this is a one-game-at-a-time, any-given-Sunday kind of game - as coaches and players on all 32 NFL teams are quick to tell us - the Denver Broncos' fourth consecutive blowout win has provided more than enough of a sample size to ask the legitimate question.

Who on earth is going to stop Peyton Manning?

"Four teams have tried to stop them, and they haven't yet," said Philadelphia coach Chip Kelly after his team's 52-20 loss Sunday.

Kelly can appreciate good offense, but for the Eagles' first-year coach, it was no time for admiration. As Kelly stood on the visitors' sideline, he watched as his helpless defense allowed Manning to lead the Broncos on three 80-yard touchdown drives in the third quarter, each culminating with a Manning touchdown toss. The Eagles couldn't answer any of those scores. And by the end of the quarter, the Broncos had turned a 21-13 halftime lead into a rout.

"I wasn't sitting there saying, 'Hey, that was a really cool play by Peyton.' He frustrates you," Kelly said.

But perhaps the most impressive feat about those drives was that not once as the Broncos covered those 240 yards and scored those 21 points did they need to convert a third down. On those drives, Manning completed passes to six different Broncos (receivers Demaryius Thomas, Wes Welker and Eric Decker, running backs Knowshon Moreno and Ronnie Hillman and tight end Julius Thomas) â?? a problem no defensive coordinator has yet to solve.

Monte Kiffin of the Dallas Cowboys gets the next shot in Week 5 at AT&T Stadium. But quarterback Tony Romo and coach Jason Garrett would be wise to learn from the failures of Kelly's vaunted offense. If Manning leads the Broncos to a touchdown, you better score one, too.

Philadelphia responded to two early Broncos' touchdowns (a pass from Manning to Welker, and a 105-yard kickoff return by Trindon Holliday) with field goals, and in the third quarter, as Manning and the Broncos really got hot, Michael Vick and the Eagles picked up only one first down in two possessions.

For the first time in the Broncos' four-game winning streak, Manning finally showed he might be enjoying this.

In his eight and a half minute postgame press conference, Manning twice said he enjoyed the win against the Eagles (there was no such admission after beating the Baltimore Ravens, New York Giants or Oakland Raiders) while he name-checked his older brother Cooper (who inspired his love of NFL trivia), 1960s-era NFL quarterback Milt Plum (whom Manning tied Sunday for the most touchdowns without an interception to start a season) and the Broncos' Arabian horse mascot, Thunder, who sprints the length of the field after each score.

Manning was given a heads up by team staff he might be asked about Plum, but he wasn't tipped off that the Broncos' 52 points were the most ever scored by the team in a single game.

"May have to give ol' Thunder an IV after that one," Manning said.

Yes, the 37-year-old is still slinging the one-liners as easily as he's tossing touchdowns and breaking records. Among the historic marks he reached Sunday was passing Kurt Warner's (1999) and Don Meredith's (1966) record of 14 touchdowns through four games. Manning tied and surpassed that record, which now stands at 16.

He is also in the midst of a streak of 201 consecutive regular season passing attempts without an interception, dating back to a Dec. 23 game against Cleveland last season â?? the longest stretch of his career.

"I enjoyed that. That was a good team we played," Manning said. "We were motivated to be on top of our game offensively, to score points, touchdowns not field goals. I thought we did that today. We certainly enjoyed that."

The Eagles meanwhile return to Philadelphia facing questions about how much progress has been made from the team that was in disarray in 2012. The blowout loss on Sunday was a painful reminder of the season that led to Andy Reid's dismissal, Kelly's arrival and a complete overhaul of the offense.

That change has led to a lot of yards - 450 more of them in Denver, but not nearly enough points in three consecutive losses to teams from the AFC West.

"This is a tough-ass league," Kelly said, adding he will have a better answer after gauging the demeanor of his players this week. "If we come out and we're hanging our heads feeling sorry for ourselves, then I'll say we didn't have any progress or growth. â?¦ They come back to work on Tuesday, then I'll be excited about this group and we move forward."